Duncan has consistently shown little patience for critics of the Common Core State Standards, being implemented in 45 states and the District of Columbia. But his remarks, as reported by Politico, went a step further and add elements of race and class.

“It’s fascinating to me that some of the pushback is coming from, sort of, white suburban moms who — all of a sudden — their child isn’t as brilliant as they thought they were and their school isn’t quite as good as they thought they were, and that’s pretty scary,” Duncan said Friday in Richmond, Va. “You’ve bet your house and where you live and everything on, ‘My child’s going to be prepared.’ That can be a punch in the gut.”

The Education Department said no official transcript of the remarks exists, but did not dispute Politico’s account.

In a late-Monday posting on the Education Department’s website, Duncan said “every demographic group has room for improvement.”

“A few days ago, in a discussion with state education chiefs, I used some clumsy phrasing that I regret — particularly because it distracted from an important conversation about how to better prepare all of America’s students for success,” Duncan said in his posting.

Duncan did not apologize and his statement was unlikely to quiet the outcry from his strongest critics, many of them online where anti-Common Core activists have organized.

Conservative columnist Michelle Malkin called Duncan a “corrupt and bankrupt bigot” for his remarks. American Federation of Teachers president Randi Weingarten said Duncan “really doesn’t get it.” Rep. Steve Stockman, R-Texas, tweeted that Duncan “should be fired for dismissing (hashtag)CommonCore critics as just white suburban moms with dumb kids.”

At the White House, spokesman Jay Carney said he hadn’t seen Duncan’s full comments or spoken with President Barack Obama about them. But Carney seemed to defend Duncan’s sentiment.

“I can just tell you that the secretary of education and everybody on the president’s team dedicated to this effort is focused on making sure that we do everything we can, working with states and others to ensure that our kids are getting the education they need for the 21st century,” Carney said.

When schools shift to standardized tests based on Common Core standards, scores generally fall. Duncan has long warned of those first-year tumbles and says the lower scores more accurately reflect the reality at the school.

Education Department communications chief Massie Ritsch said the secretary was noting that the higher standards sometimes reveal “that good schools aren’t as strong as parents in those areas have long assumed.”

The Common Core State Standards were a project of the nation’s governors and state school chiefs that aims to improve students’ readiness for life after high school. The standards outline grade-by-grade skills students should learn although the actually lessons to teach them are left to each school.

Under Common Core, students are encouraged to do more critical thinking. It’s no longer good enough for students to recall facts and figures, but they have to demonstrate why things work the way they do.

Some opponents of the standards say they are a one-size-fits-all approach that isn’t appropriate. Other critics say the standards put too much emphasis on high-stakes testing and punish teachers for students’ stumbles. Some oppose the standards because the Obama administration used them as a requirement for states to receive money from the economic stimulus bill.